specifics in Spear fighting combat

[PMBardunias]

I don't seee much difference between the underhand low and the underhand high representations.

I'm somewhat limited by the images I have from vases, but I tried to get close. Underhand and overhand are less than clear. Lets call it thumb-toward-point and thumb-toward-sauroter to differentiate the grips. From this basic difference you can strike with a spear over the full range of motion of the arm. With a thumb-toward-point strike you can strike over a range from the knuckles touching your thigh, to the arm held out sideways, ending as you raise your arm awkwardly to strike from above with the knuckles facing away from your head. You have the additional option of tucking the spear up under your arm, like a lancer, and jabbing out. (This last position has been advocated here on Rat in the Roman section for late roman spears on a recent thread).

The thumb-toward-sauroter hold is more limiting. You can strike in a range from over your head to a sidearm thrust- beyond this the wrist cannot be turned to keep the point forward.

I borrowed from Leonardo to show the approximate range of motion: